Q/A #146 - Does Perlite Have Fluoride?

August 6, 2023

Q/A #146 - Does Perlite Have Fluoride?

I recently purchased 6 gallons of peat/perlite and I was wondering if the perlite was a horticultural grade perlite that was rinsed in RO water to leach out any fluoride. Thanks
(Submitted in MONTHYEAR.)


Our perlite is Supreme Perlite made in Portland, OR. They source their ore from Lakeview, OR, and the rock has very little in the way of extra minerals in it since it's a high silica rhyolitic rock. We've personally tested the perlite by soaking it in reverse-osmosis water; it doesn't change either the TDS or the pH of the water. We have used this brand of perlite for a couple decades with no ill effects on any of our carnivorous plants.

As for fluoride in general, that's a red herring. We're aware of a study that showed fluoride in perlite. However, that study couldn't be replicated because mineral composition of rock is dependent on location. Moreover, the manner in which perlite is manufactured makes the material inert (non-reactive). So, even if perlite had fluoride in it, it would still be safe for carnivorous plants because the fluoride would be rendered inert by the manufacturing process.

Watch our video about perlite.

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